My brother and I hiked out of Agnew Meadows late in the afternoon of August 8 -- no bugs down along the San Joaquin. No bugs later that night at the upper end of Shadow Lake, or the next day at Thousand Islands Lake, or the next day at the far west end of Thousand Islands, or below Donahue Pass, or in the Lyell Fork, and on up to Tuolumne (Aug 13). It was a completely mosquito-free trip! But it was also the driest we had ever seen these areas -- no fires allowed at any elevation outside of Yosemite (as far as we know Yosemite is allowing them below 9600').